Small internal combustion V-type engines having two to four cylinders are commonly used in non-automotive commercial applications, such as lawn mowers, construction equipment, generator sets, off-road vehicles or the like. The small size of these engines relative to their power output is a desirable feature, and efforts continue to provide an increasingly more compact engine. Because of the small number of cylinders in comparison to larger engines, such as automotive engines having four cylinders or more, providing an increasingly compact engine becomes more difficult due to the lack of options for mounting engine components, such as a coolant pump, fuel pump, carburetor, control system, and the like, to the engine crankcase.
A typical small V-type internal combustion engine, suitable for industrial or commercial use, has a crankcase with cylinders formed therein. The cylinders are arranged to form a V and receive reciprocating pistons which rotatably drive the crankshaft. In an effort to provide compact engines, prior art engines position various engine components, such as a coolant pump, fuel pump, carburetor, control system, and the like in a V space defined by the engine cylinders. Although positioning these components within the V-space reduces the engine size, it complicates the engine design and makes servicing these components difficult because of the space limitations.
One particular prior art vertical shaft V-type engine disclosed in U.S. Pat. No. 4,756,280 has a coolant pump disposed in the V-space on a bottom face of the crankcase. As discussed above, locating the coolant pump within the V-space complicates the engine. Furthermore, mounting the pump on the bottom face of the crankcase does not enhance the engine compactness, but does make servicing the pump more difficult.
In a non-analogous six cylinder horizontal V-type engine disclosed in U.S. Pat. No. 5,279,265, the coolant pump is disposed outside of the V-space, however a coolant distribution chamber receiving the coolant discharged by the pump is disposed in the V-space defeating the purpose of removing the pump from the V-space to provide a compact engine. This particular engine also has a complicated chain drive wherein the engine timing chain also rotatably drives the coolant pump and renders pump maintenance difficult.